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<meta charset="utf-8">
<script src="jquery/1.10.2/jquery.min.js">
	
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<script>
	$(document).ready(function() {
		$("button").click(function() {
			$("h1,h2,p").removeClass("blue");
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<style type="text/css">
.important {
	font-weight: bold;
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.blue {
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	<h1 class="blue">标题 1</h1>
	<h2 class="blue">标题 2</h2>
	<p class="blue">这是一个段落。</p>
	<p>这是另外一个段落。</p>
	<br>
	<button>从元素中移除 class</button>
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